Cycloaddition of Aroyl/Acylketene<i>S,N</i>-Acetals with Tosyl Azide: Synthesis of Novel 4-Aroyl/Acyl-5-amino-1<i>H</i>-1,2,3-triazoles and 3,4-Annulated 1,2,3-Triazoles
作者:R. T. Chakrasali、H. Ila、H. Junjappa
DOI:10.1055/s-1988-27728
日期:——
Cycloaddition of aroyl- and acylketene S,N-acetals 1a-l with tosyl azide 2 under alkaline conditions affords novel regiospecifically substituted 4-aroyl/acyl-1-phenyl/alkyl-5-tosylamino-1H-1,2,3-triazoles 5a-1. Some of them (5a-e, g, h) are shown to undergo facile detosylation in the presence of concentrated sulfuric acid to give the corresponding 5-aminotriazoles 6a-e, g, h in excellent yields. The reaction of cyclic S,N-acetals 8a-c with 2 in dioxane at higher temperature yields the corresponding bicyclic 3-aroyl-5,6-dihydrothiazolo[3,2-c] [1,2,3]-triazoles 10a-c in good yields.
在碱性条件下,芳基和酰基乙烯基 S,N-乙醛 1a-l 与甲苯基叠氮化物 2 环加成,可得到新的区域特异性取代的 4-芳酰基/酰基-1-苯基/烷基-5-对甲苯磺酸氨基-1H-1,2,3-三唑 5a-1。研究表明,其中一些(5a-e、g、h)在浓硫酸存在下容易发生去甲基化反应,从而以极好的收率得到相应的 5-氨基三唑 6a-e、g、h。环状 S,N-乙醛 8a-c 与 2 在二噁烷中于较高温度下反应,可得到相应的双环 3-芳酰基-5,6-二氢噻唑并[3,2-c] [1,2,3]- 三唑 10a-c,收率很高。